1. Field of the Disclosure
This disclosure relates to microgrid electrical power distribution systems. Specifically, the disclosure addresses the resilient control of microgrids in response to overall conditions to which the microgrid is subjected.
2. Description of the Art
The term “microgrid” is defined as a group of interconnected loads and distributed energy resources (DER) within clearly defined electrical boundaries that act as a single controllable entity with respect to the grid and can connect and disconnect from the grid, operating in grid-connected or island mode.
Microgrid systems have been recognized as one of the primary technical approaches for improvements in the electrical grid's efficiency, reliability, and resiliency. The U.S. Department of Energy has indicated that microgrid systems will aid in meeting specific objectives for energy resilience, including protection of critical infrastructure and public resources. While it is expected that those objectives will vary depending on regional and other circumstances, the focus should be on strengthening the resilience of electrical infrastructure against adverse effects of future extreme weather phenomena and other unforeseen occurrences, so as to support efforts to prepare the nation for the impacts of climate change (as set forth in Executive Order 13653) and the goal of “building stronger and safer communities and infrastructure” in accordance with the President's Climate Action Plan.
In order to build a more resilient electrical grid it is necessary that microgrids that are supporting the main grid are themselves resilient. Due to its ability to continue operating when electricity delivered from a utility is disrupted, a microgrid is considered a strategic asset to support the planning and implementation of resilient energy communities. Microgrids can improve the ability of communities to adapt to changing conditions and withstand, respond to, and recover rapidly from disruptions caused by weather-related and other naturally occurring or unnatural events. The microgrid must be capable of managing its resources to meet the community-defined resilience objectives during disruptive events, and providing sufficient information to distribution system operators to enable the communication of accurate information on operating conditions of the microgrid to communities, especially those responsible for critical loads. The control architecture for such a microgrid is still an active area of research. During normal situations, centralized control architecture may be best for optimal operation of a microgrid. During abnormal conditions (e.g., a storm), however, a centralized control solution can suffer from a single point of failure. Further, too much computational time may be needed for determining and implementing new control actions to avert a dynamic situation transforming into a catastrophic scenario, and, in the case of communication failures, control operation may fail.
There is therefore a need in the art for a microgrid control architecture that does not have a single point of failure susceptible to extreme conditions.
There is furthermore a need for a microgrid control architecture that requires a minimum of computational time for determining and implementing new control actions to avert a developing dynamic situation transforming into a catastrophic scenario.
There is an additional need in the art for a microgrid control architecture that functions adequately in cases where communications connections between microgrid components are not functional. The control architecture should, however, provide advanced microgrid functions regarding efficiency, cost and conservation under normal operating conditions.